Despite many decades of prevention efforts, alcohol related traffic injuries and deaths due to drinking and drunken driving remain major problems in communities throughout the US. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has recently sponsored an extensive study of the etiology of these problems across mid-size cities in California and is currently supporting an evaluation of community-based environmental preventive interventions intended to reduce these problems in 24 of these cities. One of the primary concerns of these studies has been to identify the ecological causes and correlates of drinking and drunken driving in order to better tailor prevention efforts. If we can identify the primary sources of drinking drivers in community settings, we can tailor prevention efforts to drinkers in those settings and develop effective behavioral ecological interventions. The challenges are to develop a comprehensive representation of sources of drinking and drunken driving in community settings, and then use that information to guide prevention efforts. Progress on these efforts will be discussed.